Bug #334 UDF can't work
Submitted: 27 Apr 2003 0:17 Modified: 16 May 2003 18:16
Reporter: Meng Wang Email Updates:
Status: Closed Impact on me:
None 
Category:MySQL Server: User-defined functions ( UDF ) Severity:S4 (Feature request)
Version:4.0.12 / 4.1.0 OS:Windows (windows 2000 / XP)
Assigned to: CPU Architecture:Any

[27 Apr 2003 0:17] Meng Wang
Description:
i hava use UDF in windows, the UDF librayr compile as a dll. 

i use qurey ::

CREATE FUNCTION valid_date RETURNS STRING SONAME "udf.dll";

mysql response ::

can't find function 'valid_date' in librayr.

i complie 'udf_example.cpp' some as  can't work too.i can't try in MySQL v3.x.

this a bugs or other?

please help me.

thanks.. :)

HeartIcy
HeartIcy@163.com

How to repeat:
[16 May 2003 18:16] MySQL Verification Team
Sorry this isn't a bug.
Below I pasted a sample I did sometime ago for another user:

Ok. Assuming you have VC++ and the source distribution and a server running,
I will create a UDF that returns a name:

Note: the sample is ugly, but the purpose here is to show you how
to handle the UDF.

- Open the mysqld.dsw workspace.
- Add New project to the workspace
- Project name: my_udf
- Select Win32 Dynamic-Link Library
- Click OK
- Select An Empty DLL project
- Click Finish
- Click OK
- Add a new file called my_udf.cpp to the project:

#include <stdlib.h>
#include <winsock.h>
#include <mysql.h>

extern "C" {
char *my_name(UDF_INIT *initid, UDF_ARGS *args, char *is_null,
		     char *error);
}

char *my_name(UDF_INIT *initid, UDF_ARGS *args, char *is_null,
		     char *error)
{
    char * me = "my name";

    return me;
}

- Type Ctrl+N for to create a new file.
- Select text type
- File name: my_udf.def
- Edit the above file with the below contents:
LIBRARY         UDF_EXAMPLE
DESCRIPTION             'Example Using UDF with VC++'
VERSION         1.0
EXPORTS
        my_name

- Right Click the my_udf project and select Settings
- Click the C/C++ tab
- Select General in the Category Combo
- Add the macro HAVE_DLOPEN to the PreProcessor definition
- Select Preprocessor in the Category Combo
- Add the include path to the text box: Additional Include directories
  e.g: ../include
- Press F7 for to build the DLL.

- Copy the my_udf.dll to the environment path directory:
  \winnt\system32 for example.

- Start the mysql client and issue:

C:\mysql-udf\bin>mysql -uroot -p
Enter password:
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 2 to server version: 3.23.52-max-nt

Type 'help;' or '\h' for help. Type '\c' to clear the buffer.

mysql> CREATE FUNCTION my_name RETURNS STRING SONAME "my_udf.dll";
Query OK, 0 rows affected (0.08 sec)

mysql> select my_name();

mysql> drop function my_name;
Query OK, 0 rows affected (0.00 sec)